Dietary Phenolic Compounds Interfere with the Fate of Hydrogen Peroxide in Human Adipose Tissue but Do Not Directly Inhibit Primary Amine Oxidase Activity

Figure 7

Chemical structures and proposed mechanism of action of phenolic compounds in the Amplex Red-based fluorometric determination of amine oxidase activity in tissue preparations. The tested phenolic compounds with given structures did not behave as full inhibitors of MAO and SSAO present fat tissue, since only resveratrol partially inhibited [¹⁴C]-tyramine oxidation by human subcutaneous adipose tissue. However, all of them inhibited hydrogen peroxide detection by preventing the oxygen species from reacting with horseradish peroxidase (HRP) and hampering the generation of the oxidized Amplex Red, that is, the fluorescent probe, resorufin.